The term "North Germanic languages" is used in genetic linguistics, while the term "Scandinavian languages" appears in studies of the modern standard languages and the dialect continuum of Scandinavia.

In medieval times, speakers of all the Scandinavian languages could understand one another and they referred to it as a single language called the "Danish tongue" until the 13th century in Sweden and Iceland. In the 16th century, Danes and Swedes still referred to North Germanic as a single language, which is stated in the introduction to the first Danish translation of the Bible and in Olaus Magnus' A Description of the Northern Peoples.

Yet, by 1600, the genetic East Scandinavian and West Scandinavian branches had become reconfigured from a syntactic point of view into an insular group (Icelandic and Faroese) and a continental group (Danish, Norwegian and Swedish). The division between Insular Scandinavian (ö-nordisk/ø-nordisk) and Continental Scandinavian (Skandinavisk) developed due to different influences, and is based on the degree of mutual comprehensibility between the languages in the two groups.

Classification

In historical linguistics, the North Germanic family tree is divided into two main branches, West Scandinavian languages (Norwegian, Faroese and Icelandic) and East Scandinavian languages (Danish and Swedish), along with various dialects and varieties. The two branches are derived from the western and eastern dialect group of Old Norse, respectively. There was also an Old Gutnish branch spoken on the island of Gotland. The East Scandinavian languages (and modern Norwegian, through Danish) were heavily influenced by Middle Low German during the period of Hanseatic expansion.

Currently, English loan words are influencing the languages. A 2005 survey of words used by speakers of the Scandinavian languages showed that the number of English loan words used in the languages have doubled during the last 30 years and is now 1.2%. Icelandic has imported fewer English words than the other Scandinavian languages, despite the fact that it is the country that uses English most.

Another way of classifying the languages—focusing on mutual intelligibility rather than the tree of life-model—posits Norwegian, Danish, and Swedish as Continental Scandinavian, and Faroese and Icelandic as Insular Scandinavian. Because of the long political union between Norway and Denmark, Traditional Standard Norwegian (Riksmål and Bokmål) share most of the Danish vocabulary and grammar, and was virtually identical to written Danish until the spelling reform of 1907. (For this reason, Riksmål and Bokmål is sometimes considered East Scandinavian, and Nynorsk West Scandinavian via the West-East division shown above.) However, Danish has developed a greater distance between the spoken and written versions of the language, so the differences between spoken Norwegian and Danish are somewhat more significant than the difference between the written. In writing, Danish is relatively close to the other Continental Scandinavian languages, but the sound developments of spoken Danish include reduction and assimilation of consonants and vowels, as well as the prosodic feature called stød in Danish (lit. "push; thrust"), developments which have not occurred in the other languages. However, Scandinavians are widely expected to understand the other spoken Scandinavian languages. Some people may have some difficulties, particularly older people who speak a dialect, but most people can understand the standard languages, as they appear in radio and television, of the other Scandinavian countries.

The lowest degree of intelligibility is between spoken Danish and Swedish. The relationships between the three languages Danish, Norwegian and Swedish may be summarized as per the following diagram; Norwegian is sometimes referred to as "Danish spoken with a Swedish accent":

Mutual comprehensibility

The mutual comprehensibility between the Continental Scandinavian languages is asymmetrical. Various studies have shown Norwegian-speakers to be the best in Scandinavia at understanding other languages within the language group. According to a study undertaken during 2002–2005 and funded by the Nordic Cultural Fund, Swedish-speakers in Stockholm and Danish-speakers in Copenhagen have the greatest difficulty in understanding other Nordic languages. The study, which focused mainly on native speakers under the age of 25, showed that the lowest ability to comprehend another language is demonstrated by youth in Stockholm in regard to Danish, producing the lowest ability score in the survey. The greatest variation in results between participants within the same country was also demonstrated by the Swedish-speakers in the study. Participants from Malmö, located in the southernmost Swedish province of Scania, demonstrated a better understanding of Danish than Swedish-speakers to the north. Access to Danish television and radio, direct trains to Copenhagen over the Öresund bridge and a larger number of cross-border commuters in the Oresund Region contribute to a better knowledge of spoken Danish and a better knowledge of the unique Danish words among people in Scania. According to the study, Scanian youth were able to understand the Danish language better than the Norwegian language.

The results from the study of how well native youth in different Scandinavian cities did when tested on their knowledge of the other Continental Scandinavian languages are summarized in table format, reproduced below. The maximum score was 10.0:

Faroese speakers (of the Insular Scandinavian languages group) are even better than the Norwegians at comprehending two or more languages within the Continental Scandinavian languages group, scoring high in both Danish (which they study and use at school) and Norwegian and having the highest score on a Scandinavian language other than the mother tongue, as well as the highest average score. When speakers of Faroese and Icelandic were tested on how well they understood the three Continental Scandinavian languages, the test results were as follows (maximum score 10.0):

The North Germanic languages are often cited as proof of the aphorism "A language is a dialect with an army and navy." The differences in dialects within the countries of Norway, Sweden, and Denmark can often be greater than the differences across the borders, but the political independence of these countries leads continental Scandinavian to be classified into Norwegian, Swedish, and Danish in the popular mind as well as among most linguists. This is also because of the strong influence of the standard languages, particularly in Denmark and Sweden. Even if the language policy of Norway has been more tolerant of rural dialectal variation in formal language, the prestige dialect often referred to as "Eastern Urban Norwegian", spoken mainly in and around the Oslo region, can be considered to be quite normative. The creation of Nynorsk out of dialects after Norway became independent of Denmark in 1814 was an attempt to make the linguistic divisions match the political ones.

Family tree

All North Germanic languages are descended from Old Norse. Divisions between subfamilies of North Germanic are rarely precisely defined: Most form continuous clines, with adjacent dialects being mutually intelligible and the most separated ones not.

Beside the two official written norms of Norwegian, there exist two established unofficial norms: Riksmål, similar to, but more conservative than Bokmål, which is used to various extents by numerous people, especially in the cities and Høgnorsk "High-Norwegian", similar to Nynorsk, used by a very small minority.

Jamtlandic shares many characteristics with both Trøndersk and with Norrländska mål. Due to this ambiguous position, it is contested whether Jamtlandic belongs to the West Norse or the East Norse language group.

Älvdalsmål "Älvdalen Speech", generally considered a Sveamål dialect, today has an official orthography and is, because of a lack of mutual intelligibility with Swedish, considered as a separate language by many linguists.

Other languages in Scandinavia

Sami languages form an unrelated group that has coexisted with the North Germanic language group in Scandinavia since prehistory. Sami, like Finnish, is part of the Finno-Ugric language group. In inter-Nordic contexts, texts are today often presented in three versions: Finnish, Icelandic, and one of the three languages Danish, Norwegian and Swedish.

The North-Germanic languages are majority languages in Denmark, Norway and Sweden, while Finnish is spoken by the majority in Finland. Another language in the Nordic countries is Kalaallisut language, one of the official languages of Greenland beside Danish.

In southernmost Denmark, German is also spoken, being an official language there. Traditionally, Danish and German were the two official languages of Denmark-Norway.